This application is related to and claims priority from Japanese Application No. 2000-291952, filed Sep. 21, 2000.
The present invention relates to a method and apparatus for inspecting particles or defects, and more particularly, to a method and apparatus for inspecting particles or defects for use in inspecting particles existing on thin film substrates, semiconductor substrates, photomasks and so on, and pattern defects encountered on patterns on such materials, and analyzing the cause of the defects in the manufacturing of semiconductor chips and liquid crystal products, wherein the method and apparatus of the invention display an inspection result in such a form that enables the user to readily analyze the result and rapidly identify the cause of failure.
Conventionally, the technology for detecting defects on semiconductor devices and so on using an optical measuring means has been widely known. For example, xe2x80x9cSemiconductor Wafer Inspection Apparatusxe2x80x9d described in JP-A-62-89336 discloses a technique for irradiating a semiconductor substrate with a laser to detect scattered light from particles, if attached on the semiconductor substrate, and comparing the detected scattered light with the result of an inspection, which has been made immediately before on the same type of semiconductor substrate, to inspect the particles or defects.
Also, xe2x80x9cMethod and Apparatus for Measuring Information on Particle or Defect Sizexe2x80x9d described in JP-A-5-273110 discloses a method of measuring sizes of particles or crystal defects, which involves irradiating an object under inspection with a laser beam, receiving scattered light from possible particles or crystal defects on the object under inspection, and processing the scattered light to generate an image of the object under inspection on which the sizes of particles and crystal defects are measured.
Also, xe2x80x9cYield Monitoring and Analysis in Semiconductor Manufacturingxe2x80x9d in prescripts of VLSI technology Seminar, pp. 4-42-4-47, in SEMICON Kansai, 1997, discloses an approach for analyzing the yield from particles detected on a semiconductor wafer.
Conventionally, as an approach for managing product manufacturing processes in manufacturing lines for semiconductor substrates, thin film substrates and so on, a management approach is employed for monitoring particles and defects on substrates. Such a monitoring method involves inspecting particles or pattern defects on substrates by use of an apparatus for inspecting particles or defects, monitoring a transition of the number of particles or defects detected by the inspection apparatus, and conducting a failure analysis on the particles or defects on substrates, from which a large number of particles or defects have been detected.
However, this prior art approach requires a total time for the failure analysis equal to the product of the number of detected particles/defects and a time required for the failure analysis on one particle/defect. Particularly, the failure analysis requires a prohibitively long time when the particle/defect inspection apparatus detects a large number of particles or defects, thereby giving rise to a problem that the manufacturing of substrates is delayed.
The present invention has been made to solve the problem of the prior art as mentioned above, and provides a method and apparatus for inspecting particles or defects for use in inspection and failure analysis on processes for manufacturing semiconductor wafers and thin film substrates, which are capable of performing an inspection in accordance with sizes of particles and pattern defects or the characteristics of each region on an object under inspection to take prompt countermeasures to a failure.
Specifically, the present invention provides a particle/defect inspection apparatus for measuring an object under inspection in accordance with an optical approach to detect particles or defects thereon. The inspection apparatus includes illuminating means for illuminating light to an object under inspection, light detecting means for detecting reflected light or scattered light from the object under inspection, detecting means for detecting particles or defects based on a signal detected by the light detecting means, dimension measuring means for processing the signal detected by the light detecting means to measure the size of each particle or defect, data processing means for processing an inspection result, and display means for displaying information on the inspection result, wherein the data processing means relates a particle or defect size to a cause of failure to point out the cause of failure from statistical processing on the inspection result, and the display means displays information on the inspection result.
The present invention also provides a particle/defect inspecting method for measuring an object under inspection in accordance with an optical approach to detect particles or defects thereon. The inspecting method includes a procedure for illuminating light to an object under inspection, a procedure for detecting reflected light or scattered light from the object under inspection, a procedure for detecting particles or defects based on a detected signal, a procedure for processing the detected signal to measure the size of each particle or defect, a data processing procedure for processing an inspection result, and a procedure for displaying information on the inspection result. The procedures are executed in this order to relates a particle or defect size to a cause of failure, wherein the data processing procedure points out a cause of failure from statistical processing on the inspection result to display information on the inspection result.
These and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings.